Interacoustics AT235 Mode D'emploi page 229

AT235 Instructions for Use - US
Height above sea level The pressure sensor used, is a differential/gauge type, which means, it measure
Temperature
Reflex Calibration Standards and Spectral Properties:
General
Contralateral Earphone Pure tone:
Ipsilateral Earphone
The risk of artifacts at higher stimulus levels in reflex measurements are minor and will not activate the
reflex detection system
the pressure difference and therefore not affected of the height above sea level.
Probe tones 0 meters
226 Hz 1.0 mmho
678 Hz 3.0 mmho
800 Hz 3.54 mmho
1000 Hz 4.42 mmho
The pressure accuracy is: ±10 daPa or 10%, whichever is greater.
To minimize the influence of temperature, barometer pressure, humidity and
height above sea level, it always recommended to calibrate the unit in the local
positions.
The temperature have no theoretic impact on the impedance calculation, but the
temperature has influence on the electronic circuits. This temperature influence for
the standard specified temperature range (15-35 °C) is inside:
Admittance can vary inside: ± 5%, ± 0.1 cm
Specifications for stimulus and audiometer signals are made to follow IEC 60645-5
Wide Band noise (WB):
Spectral properties:
Low Pass noise (LP):
Spectral properties:
High Pass noise (HP):
Spectral properties:
Pure tone:
Wide Band noise (WB):
Spectral properties:
Low Pass noise (LP):
Spectral properties:
High Pass noise (HP):
Spectral properties:
General about levels:
500 meters 1000 meters
1.06 mmho 1.13 mmho
3.19 mmho 3.40 mmho
3.77 mmho 4.01 mmho
4.71 mmho 5.01 mmho
3
, ±10
ISO 389-1 for TDH39 and ISO 389-2 for CIR.
Interacoustics Standard
As "Broad band noise" specified in IEC 60645-5, but with
500 Hz as lower cut-off frequency.
Interacoustics Standard
Uniform from 500 Hz to 1600 Hz, 5 dB re. 1000 Hz level
Interacoustics Standard
Uniform from 1600 Hz to 10KHz, 5 dB re. 1000 Hz level
Interacoustics Standard.
Interacoustics Standard
As "Broad band noise" specified in IEC 60645-5, but with
500 Hz as lower cut-off frequency.
Interacoustics Standard
Uniform from 500 Hz to 1600 Hz, 10 dB re. 1000 Hz level
Interacoustics Standard
Uniform from 1600 Hz to 4000 Hz, 10 dB re. 1000 Hz
level
The actual sound pressure level at the eardrum will
depend on the volume of the ear.
2000 meters 4000 meters
1.28 mmho 1.65 mmho
3.85 mmho 4.95 mmho
4.55 mmho 5.84 mmho
5.68 mmho 7.30 mmho
-9 3
m /Pa·s, whichever is greater.
Page 48